let arr = ['a','b','c','d','e']
//arr.push('f')尾部添加
//arr.pop()尾部移除
//arr.unshift('f')头部添加
//arr.shift()头部移除
//arr.splice(1,0,'hello')从一开始，移除0个，添加一个hello
//arr.splice(1,1)从一开始，移除一个
let stack = []
console.log(arr);
